BB machine, also called "pager", is a called user receiver in wireless paging system. In 1948, bell laboratory developed the world's first pager, named BellBoy.

BB is composed of superheterodyne receiver, decoder, control and display. It selects the useful signal to be received from the paging signal and interference transmitted by the base station, restores it to the original baseband signal of the paging machine, and generates audio (or vibration) and display digital (or letters and Chinese characters) messages.

BB machine is small in size, light in weight, low in price and low in power consumption. Pagers can receive digital and simple phrase messages, Chinese characters, documents, notices, stock market and other extensive services, and can even be used as terminals of telegrams and data networks. The sensitivity of Chinese character display or digital display pager is better than 1μV/m or 5 μ V/m; The adjacent channel selectivity is better than 6dB(VHF band); Digital display bit length is not less than 12 bits; The mean time between failures is not less than 3, hours.

Extended information:

Development history of p>BB machine in China

In p>1983, Shanghai opened the first paging station in China, and BP machine entered China. In the late 198s, pagers began to appear in China. With the maturity of science and technology and the increase of social demand, paging stations have mushroomed everywhere since 199, and the prosperity of paging market has made the competition among paging stations increasingly fierce.

in p>1993 and 1994, mobile phones began to appear slowly. Since the second half of 1995, the paging business has been gradually defeated under the powerful offensive of mobile phones, and the number of paging users has stopped increasing. In 1996, it began to decline, the number of users decreased, and the number of paging stations also dropped sharply. After 25, pagers gradually faded out of the stage in China.

operation tandem mode of BB machine

BB machine has two modes of manual tandem and automatic tandem, and the corresponding paging stations are called manual paging stations and automatic paging stations. Manual paging stations need manual operation to encode these information and send signals through the transmitter. According to the line number of the incoming call, the automatic paging station automatically finds out the phone number of the pager and sends it out at the same time, so that the paged person knows which phone is calling.

Pagers commonly used are divided into two categories: digital pagers and Chinese pagers. Digital pagers are small, cheap and practical. Chinese pager directly displays Chinese characters, and the information is easy to identify.

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